Caribon

A repetition detector written in Rust.

Why?

I don't think it's really the case in english, but in french (and possibly other languages), it is considered poor style to repeat a word too often in a text (particularly a literary text). The purpose of this tool is to assist a writer in detecting those repetitions.

Why the name?

A text is composed of words, themselves composed of characters, which in french are called caractères. In french, good is bon so caribon is essentially good characters.

Alright, this doesn't make much sense, I'll admit I just found the name funny.

How?

Internally, Caribon use a stemming library (https://github.com/lady-segfault/stemmer-rs, the Rust bindings for Snowball C implementation: http://snowball.tartarus.org/) to reduce words to their stems, which allows e.g. to see a singular and a plural as the "same" word. Then it's just counting the repetitions, and outputting HTML.

Build

You'll need Rust and Cargo, see install instructions. Then

$ cargo build

should do the job (it works with Rust 1.1). You can then run caribon either with:

$ cargo run

or by directly executing the binary (in target/debug or target/release). Since, at this moment, all caribon does is read a text on standard input and prints HTML on standard output, the latter method is preferred:

$ target/debug/caribon < some_text.txt > output.html

(If you use cargo run instead, the standard output will start with some message from Cargo, which will ruin the HTML formatting.)

You can also install the caribon binary somewhere in your path (e.g. /usr/local/bin) but currently there is no install/uninstall option, so you'll have to do it manually.

Once you have generated an HTML file, just open it with your favorite browser and see your repetitions. Note that the default binary is configured for french, if you want to use another language, you'll have to pass an option (see below). Note that though a variety of input languages are supported thanks to the Snowball stemming library, at this time only french has a (incomplete) list of common words to ignore.

Usage

Reads a file on stdint and outputs an HTML file showing the repetitions

Options:
--help: displays this message
--version: displays program version
--list_languages: lists the implemented languages
--language=[language]: sets the language of the text (default: french)
--algo=[global|local|leak]: sets the detection algoritm (default: local)
--leak=[value]: sets leak value (only used by leak algorithm) (default: 0.95)
--max_distance=[value]: sets max distance (only used by local algorithm) (default: 50)
--global_count=[relative|absolute]: sets repetitions count as absolute or relative ratio of words
                       (only used by global algorithm) (default: absolute)
--threshold=[value]: sets threshold value for underlining repetitions (default: 1.9)
--html=[true|false]: enables/disable HTML input (default: true)
--ignore_proper=[true|false]: if true, try to detect proper nouns and don't count them (default: false)
--debug=[true|false]: if true, print the internal data instead of HTML (default: false)

Examples

Here is an example of Caribon used on a (previous) version of this README, using the following command:

target/debug/caribon --language=english --algo=local --max_distance=25 --threshold=2.0 --ignore_proper=true < README.html > example.html

As you can see, it is currently not very suited for english (neither is it for technical documentation, but is not the objective). Here is an example in french, using a translation of (the beginning of) this same file, using nearly the same command:

target/debug/caribon --language=french --algo=local --max_distance=25 --threshold=2.0 --ignore_proper=true < README.fr.html > example.html

Library

It is possible to use Caribon as a library. The documentation is available here; in order to get the latest version, you can also generate it with cargo doc.

Basically, it's pretty easy:

You create a new parser with Parser::new("language") (the only trick is that it returns an Option, as all languages are not implemented, see Parser::list_languages() to get a vector of those that are implemented by the stemming library.

You can then set some parameters for the parser, e.g:

let parser = Parser::new("french")
    .unwrap()
    .with_html(true) // enable html in input (default value, so it's useless)
    .with_ignore_proper(true); // don't count repetitions for proper nouns 

The first step is to "tokenize" the string you want to parse:

let words = parser.tokenize("Some string which may or may not contain repetitions");

The second step is to detect the repetitions, using one of the three algorithms:

let detected_words = parser.detect_local(words); 
let detected_words = parser.detect_global(words, false); 
let detected_words = parser.detect_leak(words);

The final step is to display this vector of words. Caribon provides a function that generates an HTML file, which also takes as argument a threshold above which words are underlined:

println!("{}", caribon::words_to_html(&detected_words, 1.5));

(A note on this threshold: its choices depends on the detection algorithm you use (and possibly your taste and the language you write in, of course). Generally, it should be a bit above 1.0, except for detect_global (in which case, it depends whether you set is_relative to true or false).

Current features

• Basic support for french. Less than basic support for other languages supported by the Snowball (http://snowball.tartarus.org/) project.
• Count repetitions either locally (either by ignoring repetitions after a given distance, or using some leak-based algorithm) or globally.
• Detects HTML tags in input. It doesn't work with a full HTML file (containing <html>, <body> and so on) but it works fine if you use e.g pandoc -o file.html file.md.
• Outputs a basic HTML files which higlights the detected repetitions.

ChangeLog

See here.

License

Caribon is licensed under the GNU General Public License, version 2.0 or (at your convenience) any ulterior version.

Author

Élisabeth Henry <liz.henry at ouvaton.org>.

This software uses (rust bindings to) the C Stemming library written by Dr Martin Porter, licensed under the BSD License.

TODO

Library

• Render prettier output files;
• Enhance the way language-dependent list of ignored words are treated, and provide them for other languages (currently, only french, and it should be completed);
• Provide algorithm to detect repetitions of expressions, not just single words;
• Enhance documentation and add tests.

Program

• Add possibility to read and print to a file instead of stdin/stdout;
• Make a tiny webserver version so it can be used online? (Maybe more appropriate in another project)